激活血管内皮细胞非神经性M受体对不同亚型G蛋白基因表达的影响

Effects on gene expressions of G protein alpha subunits by activation of non-neuronal muscarinic receptor

目的研究G蛋白各亚型在内皮细胞上的表达分布,以及氨甲酰胆碱和毛果芸香碱的调节作用。方法培养大鼠主动脉内皮细胞,用氨甲酰胆碱和毛果芸香碱10-4mol.L-1分别孵育,6 h后提取细胞总RNA,RT-PCR方法测定G蛋白不同亚型mRNA的表达。结果G蛋白4个亚家族中的Gq/11、Gs、G i在内皮细胞有表达,而G12/13未见表达,氨甲酰胆碱和毛果芸香碱分别作用6 h后,Gs、G i家族、Gq/11家族中的G11蛋白基因表达均未发生变化,只有Gq/11家族中的Gq蛋白在氨甲酰胆碱10-4mol.L-1作用下,基因表达上调了72.7%,而相同浓度的毛果芸香碱却不影响Gq蛋白的基因表达。结论氨甲酰胆碱激活NNMR后,G蛋白4个亚家族中只有Gq/11家族中的Gq蛋白基因表达发生了变化,可以推测Gq蛋白在NNMR的信号转导中发挥了主要的作用。

Aim To study the subtypes distribution of G-proteins and modulation by carbachol and pilocarpine on gene expression in endothelial cells. Methods The rat aorta endothelial cells were cultivated and incubated with carbachol and pilocarpine at the dose of 10^-4 mol · L^-1 for 6 h. Then the total RNA was extracted. The mRNA levels of G-protein α subunits was measured by RT-PCR. Results Gq/11, Gs and Gi mRNA was detected in rat aorta endothelial cells, while G12/13 mRNA was not detected. Carbachol andpilocarpine treatment induced no changes in Gs, Gi and G11 mRNA. Gq mRNA was 72. 7% up-regulated by carbachol and unchanged by pilocarpine. Conclusion In all G-protein α subunits, only Gq mRNA was changed after activation of non-neuronal muscarinic receptor by carbachol. We can conclude that Gq-protein may play an important role in signal transduction of non-neuronal muscarinic receptor.